Kamailio's pmtu_discovery core parameter set to 1 sets the don't-fragment bit on outbound IP packets, and it defaults to 0.
Checked 2026-10-02
- Vendor
- Kamailio project
- Product
- Kamailio
- Subsystem
- core parameters
- Deployment
- on-premises
- Region
- not restricted
- Release range
- devel cookbook as of 2026-10-02
- Checked
- 2026-10-02
Sources
- Kamailio Core Cookbook (devel) — Kamailio project · tier 2 current vendor documentation · Core parameters: pmtu_discovery
Cite this note
APA
WarmTransfer. (2026, October 2). Troubleshooting failed calls caused by large SIP messages over UDP: source note sip-fragmentation-troubleshooting-kamailio-pmtu-discovery-df. WarmTransfer. https://warmtransfer.net/knowledge/claims/sip-fragmentation-troubleshooting-kamailio-pmtu-discovery-df
BibTeX
@misc{warmtransfer-claim-sip-fragmentation-troubleshooting-kamailio-pmtu-discovery-df,
title = {Troubleshooting failed calls caused by large SIP messages over UDP: source note sip-fragmentation-troubleshooting-kamailio-pmtu-discovery-df},
author = {{WarmTransfer}},
year = {2026},
url = {https://warmtransfer.net/knowledge/claims/sip-fragmentation-troubleshooting-kamailio-pmtu-discovery-df},
note = {Source note sip-fragmentation-troubleshooting-kamailio-pmtu-discovery-df, checked 2026-10-02}
}